Chemistyr C2 AQA

56g Fe combines with 32g sulphur, find the formula of Iron Sulphide.

1) Find out how many moles of each each one.

  Al = 9/27 = 1/3 mole                   Cl = 35.5/35.5 = 1 mole

2) Find the ratio    

 Al : Cl

1/3 : 1

3) Convert to whole numbers                                  

     1 : 3

4) Write formula

 AlCl 3